Seapack - Passive Desalination UnitsWithout having to hand pump, or use electrical power, the SeaPack removes pure water from the sea (by forward osmosis) and transforms it into a drink that is high in calories to provide you energy.
The SeaPack emergencydrinking water kit employs a proprietary membrane filter that is hydrophilic (attracts water), allows water to pass through, yet blocks very small contaminants due to the tight construction of the SeaPack portable desalination filter membrane.

Further details seems to indicate this might not be all that great. The unit generates 1/2 liter per 5 hours as it's claimed rate. Each person would need their own. You have to install these grape flavored sugar packs to make the process work. It's not clear from the web site how much water you could actually make before the unit would fail or if the replacement of the sugar pack also takes away the accumulated salt.

They do go on at length about filtering harmful bacteria. While it's a good thing the fact is dissolved salts are about as small a particle as you get before you are at the sub atomic level. Anything alive really is 100% gone through osmotic filtering. They make a bigger deal of it because it sounds better.

I'm not jumping up and down to get one even if I could drive over there and check it out.

Ok more details. Unit will last 10 days and comes with 5 cartridges. The cartridges cost 5 for $30 and the unit costs $99. You need 48 cartridges to last 10 days to make 25 liters of grape flavored water so you need to spend $300 for grape flavored sugar plus $99 for the unit. The unit will be toast before you use the last two packets.

I wonder if I could make my own Cherry flavor and get into the the profitable part of this operation. Selling sugar sounds like something easy to do.

I was reading a pretty extensive article about these (lost the link). They used them like crazy in Iraq, even using them with urine to obtain something drinkable. Any people who served in Iraq on the board who used one of these?

From the article I read, it seems you did indeed need one chemical pack for each "batch" of water. So.... you would have to bring along a good bunch of the chemical pack. A good invention, but not all that new, as the US Millitary has had kits similar to this (chemical only desalination) aboard aircraft for many MANY years. The old chemical desalination kits are available at millitary surplus stores.

I think it's a neat concept for inexpensive (but limited) liferaft use, but of course a hand-cranked reverse osmosis unit would be useable indefinitely, just in case you had to stay put a while.

You could do the exact same thing with honey or very thick molases.....

The membrane (probably polyethersulfone ... same as standard RO) simply keeps the 'big pieces' from passing.
Water uptake into high molecular weight solutions (sugars, etc.) is well known --- its called osmosis.

$400 for that unit for ten days, versus $600 for a Katadyn-06 Desalinator or $1300 for the bigger model. Hmmmm....Who wants to drink $400 worth of KoolAid? Might as well stock the raft with Red Bull.<G>

As you may have read, the SeaPack operates by pulling pure water out of sea water through a filter. It is called forward osmosis since it pulls water from the source instead of pushing water through a filter like reverse osmosis does.

The SeaPack accomplishes this by using a sugar syrup. The SeaPack is essentially a bag within a bag. The outer bag is shaped like an IV bag. It holds the seawater. The sugar syrup is placed into the inner bag of the SeaPack (via the green port) and the sea water is placed into the device via the red port. The inner bag is the filter.

The SeaPack is made for use in survival situations. Not for cruisers that don't want to go ashore to fill their tanks. The drink that is produced is essentially sugar water with a slight grape flavor. It is high in calories (for energy) due to the sugar that makes it work. It is lightweight and can easily fit into your kayak. It is not made for camping and daily use. It is for when you drift out to sea and need something to help keep you alive.

Someone stated that they did not want to quench their thirst with a sugary goop. The survival drink that the SeaPack produces is the same viscosity as water. No goop is produced. Please keep in mind that the drink that is produced is high in calories, water is not. We tried to get the SeaPack to turn sea water into wine, the problem is that the Vatican has the patent on that one. :-)

Another comment was "They do go on at length about filtering harmful bacteria. While it's a good thing the fact is dissolved salts are about as small a particle as you get before you are at the sub atomic level. Anything alive really is 100% gone through osmotic filtering. They make a bigger deal of it because it sounds better."

Absolutely not correct. We make a big deal of this because it is a big deal. These products are not only produced to keep unlucky sailors alive, we produce these to keep people that have to drink post hurricane Katrina water (worst stuff we've ever tested), urine and God only knows what else. Yes, the FO membrane filters salt at the atomic level and anything that is larger.

Our next product is going to allow people to turn anything that has water in it into milk. The number one way that AIDS is transmitted to children is through mothers breast milk. The next product will allow rancid, polluted water or even in drought conditions, urine to be used to produce milk. Is it going to cost more than powdered milk itself? Of course it is. But just try turning powdered milk into something that you would want to drink while in a refugee camp.

Please keep in mind that RO pumps must be cleaned and maintained on a regular basis when used.

Yes, it is pricey, but have you looked at the alternatives? A hand held reverse osmosis pump costs almost $800. Our research shows that 95% of offshore cruisers do not have a hand held RO pump. "Why?", we asked. "Cost and maintenance" were the answers.

When asked what they plan to do in an abandon ship situation a typical unplanned offshore cruiser response is "We'll just grab a Jerry can and tie it to the raft". We researched that one as well and found that in the vast majority of abandon ship scenarios the crew did not have time to take this action and was lucky to be able to grab their ditch bag and get into the raft.

The entire idea for this came about while I was sailing across the Atlantic last year on a $600,000 catamaran. I asked the skipper what we would do if we capsized. He said that we had plenty of water in one gallon jugs. The problem was that the jugs we in outside lockers that were not dogged down. I threw one over the side and watched it sink like a rock. If we had flipped, every last jug would have been out of our reach in seconds. I asked if we had a hand held RO on board. Nope, too expensive...

Someone commented that it doesn't make that much for you to drink. All USCG approved life rafts come with one pint of water per person. Not per day, one pint period. A six person life raft comes with six pints of water and that's all you get. Try surviving off of that.

Yes, the sugar syrup charges are pricey, but isn't your life worth $30 to $60? We are working on dropping the price, but since the product is 100% "Made in the USA" getting cheap labor and raw materials isn't very easy. All of the components are designed to withstand being vacuum packed into a life raft canister. Can you say that about a can of Red Bull?

Can you make your own syrup? Sure. It is basically a high dextrose solution. Go ahead if you want to...

Please let me know if you all have any other questions or comments that I need to address.

Rick, if one was planning for a crew of four to be adrift for one week...how many packs would need to be carrried for them, at what cost? And occupying how much space?

It certainly seems like a clever niche product, but it just seems bulky and expensive compared to a conventional desalinator when you're planning for more than one person and more than a day or two. A good product, but a niche product, or so it would seem. And after 10-man-days of use, all used up?

I am sure that it is a useful product. and no doubt if I am stuck in a liferaft for a couple of weeks it will be one of many items that I wished I had bought!..........but I would not spend the money on them, just in case.

"Another comment was "They do go on at length about filtering harmful bacteria. While it's a good thing the fact is dissolved salts are about as small a particle as you get before you are at the sub atomic level. Anything alive really is 100% gone through osmotic filtering. They make a bigger deal of it because it sounds better."

Unless your membrane is HIMA validated to a titre reduction of 10E7 organisms per square centimeter then what you are saying is contrary to known science and the efficacy of RO membranes. Simply put RO membranes cannot be made consistently (cracks) to the efficiency of organism reduction that you imply. You can state 'approaches' total reduction, etc. but you simply cannot be in FDA regs. compliance by 'implication'. 100% organism reduction requires a 'validated' membrane and RO membranes simply cannot be validated because of the 'inherent manufacturing defects'.

However, what you have is an entirely 'neat' idea thats sorely needed. Congratulations, I hope you do well in promoting it.
:-)

We validate our products by testing random samples at 10E8 total coliforms (Klebsiella and E. coli as specified by the EPA's Guide to Water Purifiers, which states 10E7) per 100 ml and typically achieving no detectable bacteria per 100 mls of drink after 6 to 23 hours (1 to 1.7 liters water passed) in a SeaPack throughout 15 days of use.

We claim our products are water filters that have demonstrated 6-log bacteria reduction as specified by the EPA for water purifiers.

RO membranes cannot be operated in a reverse osmosis mode (that is, with an applied pressure gradient) without weaknesses in the membrane or sealing surfaces allowing some microbes through, which is why RO membranes are typically rated at about 99.9% (3-log) bacteria reduction, though rarely tested. It is not that RO membranes can't be validated because of inherent manufacturing defects - it's because they can't be operated without inherent manufacturing defects failing under the applied pressure gradient required for RO filtering. When the defects fail, bacteria is forced through the crack by the convective flow imposed by the applied pressure gradient.

In forward osmosis, there is no applied pressure gradient across the membrane. All movement is by diffusion driven by a concentration gradient. If there is a crack, there is no convective flow through the crack because there's no driving force for flow through the crack. If the dissolved sugars can't be held back (hundreds of times smaller than bacteria) then there's no convective flow into the drink. The drink will tend to flow out of the drink compartment. Finally, the superficial velocity across the membrane is on the order of 1-3 mm/hr (typically one to two orders of magnitude slower than reverse osmosis and ultrafiltration processes).